GB1245655A - Superconductor cables - Google Patents

Abstract

1245655 Super-conducting cables SIEMENS AG 20 Dec 1968 [20 Dec 1967] 60860/68 Headings H1A and A4D A super-conducting cable comprises two conductors mutually insulated by a first stream of helium (liquid or gaseous) and cooled by a second stream of helium at a different pressure. The conductors 1, 4 may be concentrically arranged and consist of a thin layer of niobium on a foil of aluminium on a respective inner or outer support tube of aluminium, copper or lead. They are separated from each other either by a helically coiled coil of plastics filament (3) e.g. polytetrafluoroethylene Figs. 1, 2 (not shown), or a series of frusto-conical plastics spacers 13 which are apertured at 14 for the passage of the insulating helium and have slots (15) to allow them to be pushed sideways on to the inner conductor. Cooling helium flows within the inner conductor and outside the outer conductor. In another form Fig. 6 (not shown), three conductors (41) are arranged concentrically with respective tubes (43) of insulating or poorly conductive material, which are separated by a star-shaped spacer (46) and are bound together by straps (45). The conductors are separated from the tubes by spacers such as in the previous arrangements. Several conductors of any of the above forms may be arranged within an aluminium tube 22 surrounded by thermal insulation 23, 26 with an intervening aluminium shield 24 cooled by tubes 25 containing liquid nitrogen. The unit so formed is suspended by filaments 30 within a concrete tube 27 which is then evacuated.